I think Ive found the problem, I recently spent a good amount of time on the truck we have with that issue, and as mentioned in a earlier post, i Believe it was the hydraulic pump, which cured the problem, we had flow from the jet pump, but it may not have been enough for the jet pump action to draw the excess fluid out of the bell housing, and actually the way its designed, if your flow is too low you will instead, fill the bell housing, so far after checking this unit out since the replacement, the bell housing is holding a slight amount of oil on the bottom,